1. Field of the Invention
The present invention relates to a light-scattering film, a polarizing plate and an image display.
2. Description of Related Art
In an image display such as CRT, plasma display panel (PDP), electroluminescent display (ELD), field emission display (FED), surface-conduction electron-emitter display (SED) and liquid crystal display (LCD), the display performance in a bright-room environment can be enhanced by preventing reflection of an image due to reflection of outside light.
As for the method of preventing reflection of an image in the display surface of an image display, there are disclosed (1) a method where performance of making unclear the reflected image by surface scattering (antiglare property) is imparted to let the reflected image be less recognizable, and (2) a method where performance of reducing the amount of reflected light by providing a low refractive index layer on the outermost surface of the display surface (antireflection property) is imparted to let the reflected image be less recognizable (see, Japanese Patent No. 3507719 and JP-A-2003-270409).
In recent years, the market for an application using a display having a large screen and allowing a user to watch a high-quality moving picture from a relatively distant position as represented by a liquid crystal television or the like is abruptly expanding. In such an application, the display is required to display a clearer image. When the antiglare property is strong, the outline of a thing, a fluorescent lamp, a human being or the like placed in the periphery of the display and reflected on the display surface is blurred and the image projected on the display can be easily recognized (reflection is decreased). However, the light brownish looking of the display surface is strengthened and the contrast in a bright room (bright-room contrast) may decrease.
On the other hand, in the case of using a clear surface not imparted with antiglare property, a low refractive index layer having a low refractive index at the level enabling satisfactory reduction of reflection only by antireflection utilizing the thin-film interference of one low refractive index layer is not found at present and in the case of using thin-film interference of two or more layers differing in the refractive index, the color tint may be intensified or the cost may arise.
Accordingly, a slight-scattering film reduced in the reflection and at the same time, enhanced in the bright-room contrast is being demanded. Also, a light-scattering film best suitable for an image display with a large screen, reduced in the reflection and at the same time, enhanced in the bright-room contrast is being demanded.